A little while ago, The National Maritime Museum (NMM) and the Department of History and Philosophy of Science, University of Cambridge, got together to produce a really special digital library. Designed as part of the Board of Longitude Project, a good quantity of these manuscripts are from the NMM's own archive collecions and the project has made high resolution images of some of these amazing manuscripts available on line for the first time. The NMM portion can be sampled at: http://cudl.lib.cam.ac.uk/collections/nmm_mss. The project has been funded by the Arts and Humanities Research Council.
The online digital library includes, in some cases, images of the whole record, such as the Journal of Captain Cook's first voyage of discovery in HM ship Endeavour, 1768-1771 [JOD/19]. As well as the circumnavigation of New Zealand, this journal includes possibly the first European descriptions of the east coast of Australia, its plants and animals. It's a great read and very interesting to follow this pithy and practical Yorkshireman struggle to make sense of a land so utterly different from anything he'd seen in the the northern hemisphere. Well worth a look!
F4756-001 JPG: JOD/20 Journal of Capt Cook's voyage round the world in HM ship Resolution, 1772-75 (sample image).
Also included are several images from the Admiralty collection (ADM/A series) and also from the series of Lieutenant logbooks (ADM/L). A highlight is the entire collection of papers kept by Nevil Maskelyne ( http://cudl.lib.cam.ac.uk/view/MS-REG-00009-00037/1) consisting of 1292 available images. The digital library is a real supplement to the NMM archive allowing readers to navigate and locate material online before making a visit to see the records.